JTextField : Java Glossary

a single line display of text on the screen. Sometimes you permit the user to edit
it with setEditable ( true ); The equivalent in AwT is called TextField. AWT (Advanced Windowing Toolkit) TextField has an advantage over JTextfield.

Without any coding, with AWT, the user can select, copy and paste, even in an unsigned Applet. However, Applets must be signed for
copy/paste to work in Swing. Copy/paste works in Swing without signing for applications.

To control just what characters can go in the JTextField you can use a JFormattedTextField or JTextField.
setInputVerifier.